Exactly. protesting for Palestine is now viewed with suspicion by police given the proscription of Palestine Action. That was precisely the reason Kid Starver did it. To intimidate the movement into silence.

Well the question asked about the law...

De facto, the most serious misapplications of the ban on Palestine Action were very shortly afterwards (when the police officer was quoted as saying "Mentioning freedom of Gaza, Israel, genocide, all of that all come under proscribed groups"). That's unlikely to happen again. Further, those misapplications were in the context of protests, where there is a sense of urgency to the actions of the police. The actions of the Scottish parliament are not in a protest context and so there's less sense of urgency and so less room for an individual officer to wrongly connect a ban on Palestine Action to the kinds of statements supported by Palestine Action and hence to conjure up a ban on those statements.

Or in short, because the law is against the group, not the cause, it won't affect the Scottish Parliament, even though this didn't prevent any action being taken against those in support of the cause before.